Safety latch for door



April 1 1967 J. A. WILHELM 3,316,004

SAFETY LATCH FOR DOOR Filed Au 50, 1965 2 Sheets-Sheet 1 FIG. I.

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HIS AT TORN EYS April 25, 1967 J. A. WILHELM SAFETY LATCH FOR DOOR 2 SheetsSheet 2 Filed Aug. 30, 1965 I NVE IQTOR.

BY i /W 2147/4212 M IL E H H A N H O J HIS ATTORNEYS United States Patent 3,316,004 SAFETY LATCH FOR DOOR John A. Wilhelm, 349 Wainwright, San Jose, Calif. 95128 Filed Aug. 30, 1965, Ser. No. 483,579 4 Claims. (Cl. 292-267) This invention relates to a safety latch for a door and more particularly to a door check or guard which will allow the door to stand ajar yet prevent passage of a person therethrough.

As in all door checks and latches the device is related to the door and door jamb such as to releasably connect them in a manner to prevent ingress and egress of a person through the door opening. To this extent the device consists of one member secured to the inner face of a door and another member secured to the door jamb or frame for interconnection with the member on the door.

Aside from the above mentioned conventional aspects of the door latch of the present invention it is an object thereof to provide a two part door latch with safe, interconnectable units which will not snag or catch on clothing during normal use of the door opening.

It is another object to provide a simple yet effective and economical bolt and keeper therefor which when slid into effective position relative to each other, create a sturdy and strong ball and socket connection coacting with the slide support secured to the door for limiting movement of the latter beyond a desired position ajar.

These and other objects of the present invention will become apparent from a reading of the following description in the light of the drawing in which:

FIG. 1 is a horizontal section through a door and jamb illustrating the latch which embodies the present invention in non-latching position thereon.

FIG. 2 is a view similar to FIG. 1 with the latch parts in latching position.

FIG. 3 is a view showing the door ajar relative to the jamb and latched against further opening.

FIG. 4 is an elevation of the keeper portion of the latch.

FIG. 5 is an elevational view of FIG. 2 as seen from line 5-5 thereof.

FIG. 6 is a frgamentary section through the keeper and bolt of the latch as seen from line 6-6 in FIG. 3; and

FIG. 7 is an end view of FIGS. 1 and 2 as seen from the right hand side thereof.

Referring to the drawing, a door is designated D and a jamb of a door frame in which the door is hingedly mounted is designated J. The door latch embodying the present invention, designated 10, consists of the usual two parts, one 11 of which is mounted on the door and the other 12 mounted on the jamb. As in all door latches, the two parts 11 and 12 are disposed for interconnection with each other to limit opening of the door relative to the jamb but when disconnected or disengaged allow the door to be opened fully.

The novel features of the door latch of the present invention reside in details of construction now to be explained.

The part 11 consists of a metallic plate 13 secured by screws or bolts 14 in the usual manner to the inner face F of the door D. This plate has a pair of vertically spaced ears 15 and 16 formed integrally therewith adjacent one edge 17 of the plate 13. The edge 17 of the plate 13 and one edge of each ear 15 and 16 is positioned in substantial alignment with the edge E of the door D for reasons later to become apparent.

A swingable slide bolt unit 18 is mounted on the plate 13 for movement with the door D. The slide bolt unit 18 consists of a pair of integral hubs 19 offset perpendicularly relative to each other. One of the hubs 20, considered 3,3 16,004 Patented Apr. 25, 1967 ICC a mounting hub, is mounted between the spaced ears and 16 and is pivotally connected to the same by means of a pin 21 extending vertically through the hub and the two ears 15 and 16.

The other hub 22, considered a slide support, is formed with its axis transverse to, but offset inwardly from the mounting hub 20. This slide supporting hub 22 has an axial bore 23 for receiving and supporting a bolt rod 25 for sliding movement relative thereto. One end 26 of the bolt rod 25, opposite the door edge E, has a retaining groove 27 formed therein for receiving a spring steel retaining ring 28 to thereby limit sliding movement thereof through the bore 23 of the hub 22.

The other end 29 of the bolt rod 25 nearest the door edge may be threaded to or formed integrally with a bullet-like head 30. The bullet-like head 30 is of somewhat elliptical shape sectionally along the long axis of the rod and head 30 as best seen in FIG. 6. The head 30 proceeds from a small round ball like terminal end 31 toward a shoulder 32 at its juncture with the rod 25, the shoulder 32 being of slightly larger diameter than the rod 25 and curving slightly down to the meeting line 33 therewith.

The other part 12 of the latch 10 consists of a metallic plate 33 secured by screws or bolts 34 in the usual manner to the inner face I of the door jamb J in substantially the same horizontal plane as the plate 13 of the part 11. This plate 33 has a body portion 35 formed integrally therewith and extending inwardly away from the jamb I. The body portion 35 has upper and lower surfaces 36 and 37 spaced from each other a distance substantially equal to the diameter of the slide supporting hub 22.

The body portion 35 has a recess 38 formed therein with an entrance opening 39 of circular configuration along an axis extended from the bolt rod 25 so as to receive the bullet-like head 30 of the latter when the door D is in closed condition relative to the jamb J. The recess 38 is of such depth that the entire bullet-like head 30 is confined within the recess 38. The inner end or base 40 of the recess is a round cam surface conforming substantially to the ball-like terminal end 31 of the head 30. The recess 38 extends horizontally inward from the entrance opening 39 in the form of a substantially quarter segment so that the bullet-like head 30 can swing horizontally about an axis approximating the center of the balllike terminal end 31 and the conforming seat or base 40 of the recess. Consequently, as the door D swings toward open condition the entire bolt rod 25 is caused to swing horizontally about the axis of the ball-like terminal end 31 of the head 30. The head 30 is thus moved horizontally within the recess 38 angularly away from the entrance opening 39 thereof.

As this occurs, the shoulder 32 of the head 30 moves behind a pair of vertically spaced lips 41 and 42 formed on the upper and lower margins, respectively, of the recess 38. These lips 41 and 42 have their apexes spaced from each other a distance to just clear the diameter of the rod 25 at the meeting line 33 bet-ween the latter and the bullet-like head 30. The bullet-like head 30 thus becomes jambed within a keeper 43 of the recess 38, the terminal end 31 bearing against the cam-like base 40 of the recess and the shoulder 32 of the bulletlike head being confined behind the vertically spaced lips 41 and 42 of the body 35.

The rod 25 thus becomes an arm fuzlcrumed in the keeper 43 and the hub 22 slides outwardly along the rod 25 until the hub 32 engages the retaining ring 28 at the end of the rod. In this manner the door D is limited against opening beyond a maximum allowable limit.

Intermediate limit means 45 is also provided between the rod 25 and the hub 22. Part of this means 45 consists of an annular groove 46 formed in the rod 25. Several such grooves may be employed. The other part of the means 45 consists of a leaf plate 47 pivotally mounted on a pin 48 between a pair of ears 49 formed on the upper side of the back half of the hub 22. The hub 22 has a slot- 50 cut therethrough in alignment with the space between the ears 49 to allow the leaf plate 47 to pass into engagement with the rod 25.

The leaf plate 47 is swingable between two positions, one ineffective and the other effective to engage the bar 25 as best seen in FIG. 7. When the leaf plate 47 is in effective position it rides by gravity upon the surface of the slide bar 25 exposed at the slot 50. The annular grooves 46 in the slide bar 25 are slightly wider in width than the slot 50 and the leaf plate 47. Consequently, when any one groove 46 registers with the slot 50 the leaf plate 47 will gravitate into the groove 46 and thereby limit sliding movement of the rod 25 relative to the hub 22. Moreover, the door standing ajar is latched against any swinging movement thereby preventing momentum of the door aiding an intruder in breaking in. However, when the leaf plate is swung back into ineffective (dotted line FIG. 7) position, the door D can be swung back into closed position relative to the jamb J. Thereafter, the bolt rod 25 can be slid back in the slide support hub 22 to withdraw the bullet-like head 30 on the rod from the keeper recess 38. The door can now be opened.

It should here be noted that the vertical hub 20 is frictionally held between the cars and 16 on the plate 13 mounted on the door. spring washer 51 mounted on the pin 21 between the upper end of the hub and the upper ear 15 of the mounting plate 13. In this manner, the slide bolt bar and the offset hubs 20 and 22 are deterred from swinging about during movement of the door in the normal manner.

While I have described my improved safety latch for a door in specific detail it will be appreciated that the same may be susceptible to modification, alteration and/or variation without departing from the spirit of my invention therein. I therefore desire to avail myself of all modifications, alterations and/ or variations as may fairly come within the purview of the following claims.

What I claim as new and desire to protect by Letters Patent is:

1. The combination with a hinged door and its frame of a door latch comprising:

a metallic plate secured to such door and having a pair of vertically spaced ears extending inwardly therefrom,

a pair of integral hubs offset perpendicular to each other, means for pivotally mounting one of said hubs between said vertically spaced cars,

a rod mounted for axial sliding movement in the other one of said hubs and for swinging movement in a horizontal plane with the latter about the pivotal axis of said one of said hubs,

said rod having an enlarged bullet-like head terminating in a shoulder at its juncture with said rod,

a metallic keeper secured to such frame and having a recess formed therein with an entrance opening adapted to receive said bullet-like head of said rod when the door is in closed condition relative to such jamb; said keeper having vertically spaced, inwardly extending lips angularly inward from the entrance opening of said recess for engaging behind the shoulder between said rod and said bullet-like head for keeping the latter within said recess when said This is accomplished by a rod is disposed angularly inward relative to the entrance opening of said recess, and

means between said other one of said hubs and said rod for limiting relative axial sliding movement of the latter relative to said other one of said hubs.

2. The structure of claim 1 wherein said one of said hubs has means between one of its faces and the adjacent ear of said pair of ears for frictionally engaging the latter to deter free swinging movement of said rod and said other one of said hubs relative to said door.

3. The combination with a hinged door and its frame of a door latch comprising:

a mounting plate secured to to such door having a pair of vertically spaced ears extending inwardly therefrom,

a pair of integral hubs offset perpendicular relative to each other, means for pivotally mounting one of said hubs between said vertically spaced ears,

a rod mounted for axial sliding movement in the other one of said hubs and for swinging movement in a horizontal plane with the latter about the pivotal axis of said one of said hubs,

said rod having an enlarged bullet-like head terminating in a shoulder at its meeting line with said rod,

a metallic keeper secured to such frame and having a recess formed therein with an entrance opening adapted to receive said bullet-like head of said rod when the door is in closed condition relative to such jamb, said keeper having a base seat conforming to the ball-like tip of said bullet-like head, the keeper recess having a depth to confine the bullet-like head of said rod and a width horizontally such as to accommodate the bullet-like head as it swings about the axis of its ball-like tip within the base seat of said recess, a pair of vertically spaced inwardly extending lips formed on the margins of said recess angularly inward from the entrance opening of said recess for engaging behind the shoulder at the meeting line of said rod and said bullet-like head for keeping the latter within said recess when said rod is disposed angularly inward relative to the entrance opening of said recess, a retaining ring on the opposite end of said rod for limiting movement of the latter from said other one of said hubs,

a leaf plate pivotally mounted on said other one of said hubs, and

an annular groove intermediate the ends of said rod for receiving said leaf plate for limiting relative axial sliding movement of said rod relative to said hub.

4. The structure of claim 3 wherein said one of said hubs has means between one of its faces and the adjacent ear of said pair of ears for frictionally engaging the latter to deter free swinging movement of said rod and said other one of said hubs relative to said door.

References Cited by the Examiner UNITED STATES PATENTS 976,403 11/1910 Shedlock 292265 FOREIGN PATENTS 154 1896 Great Britain. 26,604 1908 Great Britain. 102,945 1/1924 Switzerland.

EDWARD C. ALLEN, Primary Examiner.

RICHARD E. MOORE, Examiner. 

1. THE COMBINATION WITH A HINGED DOOR AND ITS FRAME OF A DOOR LATCH COMPRISING: A METALLIC PLATE SECURED TO SUCH DOOR AND HAVING A PAIR OF VERTICALLY SPACED EARS EXTENDING INWARDLY THEREFROM, A PAIR OF INTEGRAL HUBS OFFSET PERPENDICULAR TO EACH OTHER, MEANS FOR PIVOTALLY MOUNTING ONE OF SAID HUBS BETWEEN SAID VERTICALLY SPACED EARS, A ROD MOUNTED FOR AXIAL SLIDING MOVEMENT IN THE OTHER ONE OF SAID HUBS AND FOR SWINGING MOVEMENT IN A HORIZONTAL PLANE WITH THE LATTER ABOUT THE PIVOTAL AXIS OF SAID ONE OF SAID HUBS, SAID ROD HAVING AN ENLARGED BULLET-LIKE HEAD TERMINATING IN A SHOULDER AT ITS JUNCTURE WITH SAID ROD, A METALLIC KEEPER SECURED TO SUCH FRAME AND HAVING A 